linux-kernel - Re: [PATCH 0/2] perf kvm: Fix memory leak

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 20 Mar 2023 19:37:14 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ian Rogers <irogers@...gle.com>
Cc:     Leo Yan <leo.yan@...aro.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        James Clark <james.clark@....com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/2] perf kvm: Fix memory leak

Em Mon, Mar 20, 2023 at 10:43:11AM -0700, Ian Rogers escreveu:
> On Sun, Mar 19, 2023 at 11:16 PM Leo Yan <leo.yan@...aro.org> wrote:
> >
> > This patch seris is to address memory leak issues in perf kvm.
> >
> > The first patch introduces refcnt in structure kvm_info, so we can avoid
> > memory leak for it.
> >
> > The second patch explicitly delete histograms entries before program
> > exiting rather than relying on kernel releasing memory space.
> >
> 
> Series:
> Acked-by: Ian Rogers <irogers@...gle.com>

I applied this, but the second patch may end up delaying tool exit by
traversing data structures holding lots of objects to needless free
them.

There are places in perf where we do it conditionally for that reason.

At some point I want to try signalling we're exiting using some global
variable and then making all memory free operations become nops.

- Arnaldo


 
> Thanks,
> Ian
> 
> > Leo Yan (2):
> >   perf kvm: Support refcnt in structure kvm_info
> >   perf kvm: Delete histograms entries before exiting
> >
> >  tools/perf/builtin-kvm.c   |  6 ++++--
> >  tools/perf/util/hist.c     |  5 +++++
> >  tools/perf/util/kvm-stat.h | 37 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 46 insertions(+), 2 deletions(-)
> >
> > --
> > 2.39.2
> >

-- 

- Arnaldo